developing office addin - Could not initialize application. Error 42

Question

I have developed Office add-in (COM), I used WIX to deploy the add-in and it is working without any problem then the client asked to integrate a third party library(for license), to enable adding a license feature.

After integrated the license library(couple of dlls) and install it for testing.

The installation works fine but when opening word or excel to use the add-in it work with some machines (they were single user as administrator) but with other machines (Cooperation or having multi-users) i got error and license code is not executed(it didn't show the popup for insertion the serial key).

So the program show nothing as if the user declined to insert the serial key or use a trial version(in that case i show dialog "license invalid" and do not load my usercontrols to the task-pane). That's the error i got:

I found some articles suggest to put the DLLS in the system folders (System32 for 32 bit) and SystemWow64 for 64 bit. But then the add-in can't load the DLLS and this didn't solve the problem.

So what could be the cause of this problem? security issues or error loading the required dll?

EDIT

The third party library used for license is made by softwarekey Instant PLUS

Answer 1

Anyway i could managed to solve the problem only 3 steps:

1. Make the add-in installed for all users.
2. Give an Administrator permission for installer.
3. Run installer as Administrator.